Rolling bearing device and spindle

ABSTRACT

By incorporating a pump for sucking and discharging lubricating oil in a tank for storing the lubricating oil on an outside of a rolling bearing, for example, on a spacer for an outer ring in a housing for accommodating the rolling bearing and a nozzle in which an lubricating oil outlet communicating with a discharging port of the pump to supply the lubricating oil discharged from the pump to the rolling bearing is opened in an annular-shaped space between a fixed ring and a rolling ring in the rolling bearing, a cost is reduced by using a general-purpose rolling bearing, and at the same time, external devices and pipes for a lubrication are not required wholly or partially and problems of a noise made by compressed air are eliminated.

TECHNICAL FIELD

The present invention relates to a rolling bearing device and a spindleusing the same, and more particularly to a rolling bearing device havinga self-lubricating function and a spindle using the same.

BACKGROUND ART

For example, a rolling bearing such as an angular ball bearing is usedfor supporting rotating shafts at a comparatively high speed such asvarious spindles to be used in a machine tool. As a lubricating methodfor the rolling bearing to support the high-speed rotating shafts,conventionally, an oil air lubricating method has mainly been usedoften.

In the oil air lubricating method, a very small amount of lubricatingoil supplied intermittently is sprayed toward the rolling bearing bycompressed air through a pipe. In order to break through an air curtainformed around the rolling bearing rotated at a high speed to supply thelubricating oil to the bearing, the compressed air is used as aso-called carrier. FIG. 19 is a view including a sectional viewillustrating an example of a structure of a spindle using thelubricating method and a block diagram illustrating an example of astructure of an external device for lubrication.

This example represents a lubrication for a spindle 21 which rotatablysupports a rotating shaft 312 by means of four angular ball bearings 313in a housing 311, an oil air lubricating device 22 includes alubricating oil tank and a pump for supplying lubricating oil in thetank to a plunger for supplying a certain amount of lubricating oil inaddition to the plunger, and the lubricating oil supplied from the oilair lubricating device 22 and compressed air obtained by cleaningcompressed air sent from a compressor 23 by means of an air clean unit24 are mixed by means of a mixing valve 25 and the mixture is suppliedto the spindle 21 through a pipe 26. In the spindle 21, a hole 331 foran oil air lubrication is formed on the housing 311 corresponding toeach angular ball bearing 313, and furthermore, a hole 332 having one ofends communicating with the hole 331 of the housing 21 and the other endopposed to an annular-shaped space between an inner ring 313 a and anouter ring 313 b in the angular ball bearing 313 is also formed on aspacer 314 fixed adjacently to a fixed ring of the angular ball bearing313, that is, the outer ring 313 b in this example. A nozzle 333 isprovided in an opening portion facing an annular-shaped space of thehole 332 and oil air is jetted from the nozzle 333.

In the oil air lubricating method, it is necessary to provide an oil airlubricating device, a mixing valve, a compressor and an external pipe onthe outside of the spindle, and furthermore, to form a passage for theoil air in the spindle. Consequently, a cost is increased. In addition,there is also a problem in that a noise level is increased because thecompressed air is used.

In order to solve such a problem, there has been proposed a rollingbearing device in which a lubricating oil supply mechanism is providedin a rolling bearing (for example, see Patent Document 1).

In the proposed technique, as shown in an axial sectional view of FIG.20, an oil feeding unit comprising a tank 35 for storing lubricatingoil, a pump 36 for sucking and discharging the lubricating oil in thetank 35, a nozzle 37 attached to a discharge port of the pump 36 andextended to the vicinity of rolling elements 33 in an annular-shapedspace between an inner ring 31 and an outer ring 32 is fixed to a seal34 fixed to a fixed ring of a rolling bearing having main components ofthe inner ring 31, the outer ring 32 and the rolling elements 33, forexample, the outer ring 32, and the lubricating oil in a very smallamount of approximately several tens nl (several tens μcc) is droppedinto an inside of an air curtain formed during the rotation of therolling bearing through a tip of the nozzle 36.

According to the proposed technique, it is not necessary to providedevices and pipes on the outside of the spindle for carrying out an oilair lubrication over the rolling bearing. Moreover, it is not necessaryto form a passage for the oil air lubrication in the spindle and it isalso possible to solve the problems of noises because of non-use of thecompressed air.

Patent Document 1: JP-A-2004-108388

Patent Document 2: JP-A-2004-316707

DISCLOSURE OF THE INVENTION Problems to be Solved

In the technique disclosed in the Patent Document 1, it is necessary tocarry out a special processing over a raceway rings in order to providethe oil feeding unit in the rolling bearing. Moreover, a shape of theraceway rings is entirely different from that of a rolling bearing to beusually used.

Since it is necessary to add a special processing to the raceway ringsof the rolling bearing which originally requires a processing with highprecision, it is hard to suppress a rise in a cost. In the bearingdevice, moreover, a raceway rings having a special shape is used. Forthis reason, a general-purpose rolling bearing cannot be used but adedicated raceway rings is utilized. Also in this respect, it isdifficult to suppress the rise in the cost. Since the raceway ringshaving the special shape is used, furthermore, a width is different fromthat of the general-purpose rolling bearing so that a design iscomplicated. In addition, it is necessary to exchange the whole bearingdevice due to a failure of any of a micropump and a driving portionwhich constitute the oil feeding unit and a failure caused by any of afixed ring, a rotary ring, rolling elements and a cage.

FIG. 21A is a typical sectional view showing a nozzle for lubricantsupply provided in the oil feeding unit which is used in the rollingbearing device of FIG. 20 as seen in a radial direction of the bearing,and FIG. 21B is a view showing the nozzle seen in a circumferentialdirection of the bearing.

Moreover, the nozzle 37 for lubricant supply which is provided on thepump 36 of the oil feeding unit is formed by a pipe-shaped member shownin FIGS. 21A and 21B, and a hole (a tip hole 37 z) for discharginglubricant is provided on an end face of a tip portion 37 x. The tipportion 37 x of the nozzle 37 is disposed in a position in the vicinityof a rolling raceway of the balls 33 between a cage 39 and the outerring 32.

There has been known that a flow of air (an air current) is generated inthe circumferential direction of the bearing by the rolling motion ofthe rolling elements in the annular-shaped space of the rolling bearing.In the oil feeding unit utilizing the lubricant which is not accelerated(pressurized) in a very small amount, therefore, the tip portion 37 x ofthe nozzle 37 is inserted into the vicinity of the balls 33 in anannular-shaped space S in order to cause the lubricant to reach aninside of a barrier (an air barrier or an air curtain) by the aircurrent and to efficiently supply (drop) the lubricant into a necessaryportion.

In a conventional rolling bearing device, however, the tip of the nozzle37 is cut to take a perpendicular shape (a parallel shape with thecircumferential direction of the bearing) and the hole (the tip hole 37z) for discharging the lubricant is provided in an axial direction ofthe bearing. In some cases, consequently, an air current generated by arotation of the bearing goes around so that a negative pressure isgenerated on the tip portion 37 x and the lubricant naturally flows outof the pump 36.

In the case in which the amount of discharge of the lubricant iscontrolled by an intermittent operation of the micropump, moreover,there is a possibility that the lubricant might be discharged in anamount which is equal to or larger than an intended amount depending onconditions such as the rotating speed of the bearing.

In the conventional rolling bearing device, as shown in FIG. 22,lubricant O discharged from the hole on the nozzle tip 37X is moved in adirection of a base portion 37 b of the nozzle on the pump 36 side alongan outer peripheral surface 21 a of the nozzle by the influence of theair current and a surface tension so that a stable drop into an aimedportion is hard in some cases.

The invention has been made to attain the problem and has an object toprovide a rolling bearing device capable of accurately controlling theamount of lubricant to be supplied into an annular-shaped space withouta natural flow of the lubricant with a rotation of a bearing.

Furthermore, the invention has been made to attain the problem and has afurther object to provide a rolling bearing device capable of properlydropping lubricant into a predetermined portion and maintaining anexcellent lubrication with a small amount of the lubricant.

Means for Solving the Problems

In order to achieve the objects, the invention provides a rollingbearing device comprising a pair of raceway members which are disposedconcentrically and define an annular-shaped space therebetween, rollingelements disposed in the annular-shaped space, and a pump including apipe-shaped nozzle which is disposed in the annular-shaped space or thevicinity thereof, wherein a tip portion of the nozzle is disposed in theannular-shaped space so as to supply lubricant to the vicinity of therolling elements, and the nozzle is provided with a hole for discharginglubricating oil which is directed in a direction excluding an axialdirection and a radial direction of the rolling bearing device.

Moreover, the rolling bearing device may further comprise a cage forholding the rolling elements in the annular-shaped space, and the tipportion of the nozzle may be disposed in the annular-shaped space so asto supply the lubricant to the vicinity of the rolling elements or thecage.

The invention serves to achieve the predetermined objects by placing thedischarging port formed on the nozzle in a position in which a negativepressure caused by an air current generated by the rotation of thebearing is generated with difficulty in the rolling bearing device inwhich the oil feeding nozzle is inserted into the vicinity of therolling elements or the cage to supply the lubricant by means of thepump.

More specifically, the hole for discharging the lubricant of the nozzleis formed in a direction excluding a perpendicular direction to an aircurrent in the circumferential direction of the bearing which isgenerated in the annular-shaped space (the axial direction of thebearing and the radial direction of the bearing). Consequently, it ispossible to reduce a negative pressure generated by the air currentwhich goes around.

Moreover, it is desirable that the hole of the nozzle should be formedin a position corresponding to a circumferential direction of a bearingon a peripheral surface of the nozzle.

As compared with an end face of the nozzle tip which is flat and has ahigh probability to direct in the axial direction of the bearing, theperipheral surface of the nozzle has a large number of curved portionsopposed to the direction of the flow of the air current and the negativepressure to act on the hole can be decreased comparatively easily. Inparticular, the provision of the hole in the circumferential directionof the bearing corresponding to the direction of the air currentgenerated by the rotation of the bearing can produce the greatest effectof reducing the negative pressure. By this structure, the rollingbearing device according to the invention can accurately control theamount of the lubricant to be supplied into the annular-shaped spacewithout the natural flow of the lubricant with the rotation of thebearing.

In the invention, the number of the holes for discharging the lubricantwhich are to be provided on the nozzle is not particularly restricted.Except for the positions corresponding to the axial direction of thebearing and the radial direction of the bearing in the nozzle, it isalso possible to form a plurality of holes in the circumferentialdirection of the peripheral surface of the nozzle.

As described above, according to the invention, it is possible to obtaina compact rolling bearing device including the oil feeding unit, and atthe same time, it is possible to suppress the discharge of the lubricantin an amount which is equal to or larger than the intended amount due tothe natural flow. Thus, it is possible to obtain a rolling bearingdevice in which the oil can be automatically fed for a long period oftime. Moreover, the amount of the lubricant to be supplied into theannular-shaped space of the bearing has no waste and it is possible toprevent the troubles of the bearing such as a lubricating failure orburning caused by the earlier exhaustion of the lubricant in the storingtank than an assumed time.

In order to achieve the objects, furthermore, the invention provides arolling bearing device comprising a pair of raceway members which aredisposed concentrically and define an annular-shaped space therebetween,rolling elements disposed in the annular-shaped space, and a pumpincluding a pipe-shaped nozzle which is disposed in the annular-shapedspace or the vicinity thereof, wherein a tip portion of the nozzle isdisposed in the annular-shaped space so as to supply lubricant to thevicinity of the rolling elements, and the tip portion of the nozzle isprovided with an opening taking a shape which is opened toward anupstream side of an air current generated in the annular-shaped space bya relative rotation of the raceway members.

Moreover, the rolling bearing device may further comprise a cage forholding the rolling elements in the annular-shaped space, and the tipportion of the nozzle may be disposed in the annular-shaped space so asto supply the lubricant to the vicinity of the rolling elements or thecage.

The invention serves to achieve the predetermined objects by causing theperiphery of the discharging port of the tip of the nozzle to take sucha shape as to generate a positive pressure in the nozzle tube by the aircurrent generated by the rotation of the bearing for inserting the oilfeeding nozzle to the vicinity of the rolling elements or the cage tosupply the lubricant by means of the pump.

More specifically, the opening in the tip portion of the nozzle isformed toward an upstream side of the air current generated in theannular-shaped space by the relative rotation of the raceway members.Consequently, it is possible to reduce the negative pressure generatedby the air current which goes around and to prevent the lubricant fromnaturally flowing out.

As a specific shape of the tip portion of the nozzle, it is desirablethat an end face of the tip of the nozzle should be formed in a slantface directed toward the upstream side of the air current.

By forming the tip of the nozzle on the slant face opened toward theupstream side of the air current, the air current hits on the innerperipheral surface of the nozzle so that the lubricant is pushed towardthe inside of the nozzle by a wind pressure thereof. Accordingly, therolling bearing device according to the invention can maintain thelubricant in the nozzle tube to have the positive pressure so that theamount of the lubricant supplied into the annular-shaped space can becontrolled accurately.

In order to achieve the objects, moreover, the invention provides arolling bearing device comprising a pair of raceway members which aredisposed concentrically and define an annular-shaped space therebetween,rolling elements disposed in the annular-shaped space, and a pumpincluding a pipe-shaped nozzle which is disposed in the annular-shapedspace or the vicinity thereof, wherein a tip portion of the nozzle isdisposed in the annular-shaped space so as to supply lubricant to thevicinity of the rolling elements, and the tip portion of the nozzle isprovided with a member for leading an air current generated in theannular-shaped space by a relative rotation of the raceway memberstoward the opening.

Furthermore, the rolling bearing device may further comprise a cage forholding the rolling elements in the annular-shaped space, and the tipportion of the nozzle may be disposed in the annular-shaped space so asto supply the lubricant to the vicinity of the rolling elements or thecage.

According to the structure, similarly, the lubricant is pressed towardthe inside of the nozzle tube by the wind pressure of the air current.Consequently, it is possible to prevent the lubricant from naturallyflowing out.

As described above, according to the invention, it is possible to obtaina compact rolling bearing device including the oil feeding unit, and atthe same time, to obtain a rolling bearing device capable of suppressingthe discharge of the lubricant in an amount which is equal to or largerthan the intended amount due to a natural flow, thereby feeding the oilautomatically for a long period of time.

Moreover, the amount of the lubricant to be supplied into theannular-shaped space of the bearing has no waste and it is possible toprevent the troubles of the bearing such as a lubricating failure orburning which is caused by an unexpected situation in which thelubricant in the storing tank is exhausted earlier than an assumed time,for example.

In order to achieve the objects, furthermore, the invention provides arolling bearing device comprising a pair of raceway members which aredisposed concentrically and define an annular-shaped space therebetween,rolling elements disposed in the annular-shaped space, and a pumpincluding a pipe-shaped nozzle which is disposed in the annular-shapedspace or the vicinity thereof, wherein a tip portion of the nozzle isdisposed in the annular-shaped space so as to supply lubricant to thevicinity of the rolling elements, and lubricant holding portionprotruded at least vertically and downward from a peripheral surface ofthe nozzle is formed on the tip of the nozzle or in the vicinity of thetip.

Moreover, the rolling bearing device may further comprise a cage forholding the rolling elements in the annular-shaped space, and the tipportion of the nozzle may be disposed in the annular-shaped space so asto supply the lubricant to the vicinity of the rolling elements or thecage.

The invention serves to achieve the predetermined objects by providingthe lubricant holding portion for collecting the lubricant discharged tomake a droplet in the vicinity of the discharging port of the tip of thenozzle in the rolling bearing device for inserting the oil feedingnozzle to the vicinity of the rolling elements or the cage to supply thelubricant by means of the pump.

More specifically, the lubricant holding portion protruded at leastvertically and downward from the peripheral surface of the nozzle isformed on the tip of the nozzle or in the vicinity of the tip so thatthe lubricant discharged from the tip of the nozzle is pulled up to thelubricant holding portion and is hard to move toward the base portionside of the nozzle. Accordingly, the rolling bearing device according tothe invention can properly drop the lubricant into a predeterminedportion also in the case in which the tip of the nozzle is disposed inthe annular-shaped space in which the air current is generated by therolling motion of the rolling elements.

As specific forming means for the lubricant holding portion, it ispossible to suitably employ a method of setting the vicinity of the tipof the nozzle to have a larger diameter than diameters of the otherportions, a method of setting an opening diameter of the tip of thenozzle to be larger than inside diameters of the other portions, or amethod of fitting an annular-shaped member in an outer peripheralsurface of the nozzle.

By the structure, it is possible to easily form the lubricant holdingportion. In the case in which the nozzle takes a shape of a pipe havinga very small diameter, for example, an injection needle and it is hardto carry out a processing over the tip portion due to a shortage of astrength of the nozzle, moreover, an annular-shaped member may be fittedon an outer periphery in the vicinity of the tip.

As described above, according to the invention, also in the case inwhich the lubricant supply nozzle is disposed in the annular-shapedspace of the rolling bearing in which the air current is generated bythe rolling motion of the rolling elements, the lubricant can beproperly dropped into a predetermined portion. Moreover, the lubricantto be supplied has no waste and an excellent lubrication of the rollingbearing device can be maintained with a small amount of the lubricant.

In order to achieve the objection, furthermore, the present inventionprovides a rolling bearing device comprising:

a pair of raceway members which are disposed concentrically and definean annular-shaped space therebetween; rolling elements disposed in theannular-shaped space; and a pump including a pipe-shaped nozzle which isdisposed in a spacer disposed in the vicinity of the annular-shapedspace or the vicinity thereof, in which a tip portion of the nozzle isdisposed in the annular-shaped space so as to supply lubricant to thevicinity of the rolling elements, and the space is provided with anintermediate member between the space and one of the raceway members.

The rolling bearing device may further comprises a cage for holding therolling elements in the annular-shaped space at predetermined intervals,the tip portion of the nozzle being disposed in the annular-shaped spaceso as to supply the lubricant to the vicinity of the rolling elements orthe cage.

Further, the intermediate member may have an annular shape.

Further, at least three of the intermediate members may be disposed atconstant intervals in a circumferential direction of the space.

Further, a fitting portion fitted with the intermediate member may beformed on at least one of a space and the raceway members, which isbrought into contact with the intermediate member.

The intermediate member may have a C-shape.

In view of above, according to the present invention, since theintermediate member is disposed between the space and the fixed ring,the tip portion of the nozzle for supplying the lubricant can beadjusted to a position suitable for supplying a small amount oflubricant with respect to the ball, and thus it is possible to maintainan excellent bearing lubrication with a small amount of the lubricant.

BEST MODE FOR CARRYING OUT THE INVENTION Example 1

An example 1 according to the invention will be described below withreference to the drawings.

FIG. 1 is an axial sectional view showing a structure of a spindleaccording to the example 1 of the invention and FIG. 2 is an enlargedview showing a main part thereof. Moreover, FIG. 3 is a front viewshowing a spacer 4 for an outer ring seen in a direction of an arrow Ain FIG. 2.

A shaft 2 is rotatably supported by means of four angular ball bearings3 in a housing 1. Each of the angular ball bearings 3 comprises an innerring 3 a to be fitted and fixed into the shaft 2, an outer ring 3 bfitted over the housing 1, a plurality of rolling elements (balls) 3 cdisposed rollably therebetween, and a cage 3 d for holding each of therolling elements 3 c at a certain interval in a circumferentialdirection, and is used for various purposes.

An inner flange 1 a is formed integrally with one end side of thehousing 1 and a cover member 1 b is screwed into the other end side, anda movement of the outer ring 3 b of each of the angular ball bearings 3in an axial direction is blocked and it is thus positioned by means ofcylindrical spacers 4 . . . 4 for the outer ring and a central spacer 5which are disposed along an inner peripheral surface of the housing 1between the inner flange 1 a and the cover member 1 b, and each outerring 3 b.

Moreover, a step portion 2 a is formed on an end of the shaft 2 at aside where the cover member 1 b is fixed, and furthermore, a femalethread 2 b is formed on an end at a side where the inner flange 1 a isformed, and a bearing presser 6 is screwed into the female thread 2 b.The movement of the inner ring 3 a of each of the angular ball bearings3 in the axial direction is blocked and it is thus positioned by meansof the step portion 2 a and the bearing presser 6, spacers 7 . . . 7 foran inner ring and a central spacer 8 which are disposed along an outerperipheral surface of the shaft 2 between the step portion 2 a and thebearing presser 6, and each inner ring 3 a.

An oil feeding unit is incorporated into the spacer 4 for an outer ringwhich is disposed adjacently to each of the outer rings 3 b. The oilfeeding unit is mainly constituted by a tank 9 a for storing lubricatingoil, a pump 9 b for sucking and discharging the lubricating oil in thetank 9 a, a nozzle 9 c attached to a discharging port of the pump 9 b,and a driving circuit 9 d of the pump 9 b as shown in FIGS. 2 and 3.These are fixed along an inner peripheral surface of the spacer 4 for anouter ring. As shown in FIG. 3, the nozzle 9 c enters an annular-shapedspace between the inner ring 3 a and the outer ring 3 b in the rollingbearing 3 and is thus opened in an upper part provided just close to therolling elements 3 c. The tank 9 a and the pump 9 b communicate witheach other through a pipe 9 e.

FIG. 4 is a view showing a whole structure of the oil feeding unit,including a typical view illustrating a mechanical structure and a blockdiagram illustrating an electrical structure together.

The pump 9 b is constituted by a pump chamber 90, a diaphragm 91 forforming a wall member to be a part of the pump chamber 90, apiezoelectric unit 92 stuck to the diaphragm 91, and a check valve 93provided in a connecting portion of the pump chamber 92 and the pipe 9e. The driving circuit 9 d includes a power battery 94 and supplies arectangular voltage signal to the piezoelectric unit 92. In thestructure, the rectangular voltage signal is applied to thepiezoelectric unit 92 so that the diaphragm 91 is displaced verticallyin the drawing. The lubricating oil in the tank 9 a is sucked into thepump chamber 90 through the check valve 93 and the pipe 9 e in an upwarddisplacement of the diaphragm 91 and the lubricating oil in the pumpchamber 90 is discharged toward the nozzle 9 c in a subsequent downwarddisplacement, and the lubricating oil is dropped from a tip portion ofthe nozzle 9 c into an upper part of the rolling elements 3 c of theangular ball bearing 3. In the discharge of the lubricating oil of thepump 9 b, the lubricating oil in the pump chamber 90 is not returnedtoward the pipe 9 e side by the presence of the check valve 93. Theamount of supply of the lubricating oil to the angular ball bearing 3 isapproximately 30 nl (30 μcc). Depending on the conditions of use, theamount of supply of the lubricating oil can be changed from severalhundreds pl to several hundreds nl.

According to the example in accordance with the invention, an apparatusfor a whole lubrication is not required on the outside of the spindle,and the structure of the apparatus can be simplified and a reduction ina cost can be achieved, and at the same time, the compressed air is notused. Therefore, it is also possible to solve the problem of a noise.

While the oil feeding unit is incorporated in the spacer 4 for an outerring in the example, the invention is not restricted thereto but aposition in which the oil feeding unit is to be provided can be set intoanother position in the housing on the outside of the rolling bearing.FIGS. 5 and 6 show the example.

FIG. 5 shows the example in which an equivalent oil feeding unit to thatin the prior example is incorporated in the cover member 1 b attached toone of the ends of the housing 1. Also in this example, the nozzle 9 cattached to the pump 9 b is inserted into the annular-shaped spacebetween the inner ring 3 a and the outer ring 3 b in the angular ballbearing 3 and is thus opened, thereby dropping the lubricating oil fromabove the position placed just close to the rolling elements 3 c.

FIG. 6 shows the example in which the equivalent oil feeding unit tothat in the prior example is incorporated into the housing 1 itself, andthe central spacer 5 for the outer ring in the example of FIG. 1 iseliminated and a central part in the axial direction of the housing 1 isprotruded to be annular-shaped on an inside in place thereof, and thetank 9 a, the pump 9 b, the nozzle 9 c and the driving circuit (notshown) are incorporated into the protruded portion. These examples inFIGS. 5 and 6 can be used in combination with the example of FIG. 1, andthe oil feeding unit for each of the angular ball bearings 3 can bedisposed in an optimum position corresponding to the structure of thehousing 1.

In the invention, furthermore, it is not necessary to incorporate allthe members for constituting the oil feeding unit into an identicalmember such as a spacer or a cover member. As is illustrated in FIG. 7,it is possible to incorporate only the tank 9 a into another member.More specifically, in the example of FIG. 7, the spacer for an outerring disposed corresponding to each bearing is divided into two parts inthe axial direction and the pump 9 b, the nozzle 9 c and the drivingcircuit (not shown) are incorporated in a spacer 4 a for an outer ringat a side which is adjacent to the bearing, and furthermore, the tank 9a is incorporated in a spacer 4 b for an outer ring at the other sideand the tank 9 a and the pump 9 b are caused to communicate with eachother through the pipe 9 e extended in the axial direction. In thisexample, there is an advantage that the lubricating oil can be suppliedinto the tank 9 a by removing the spacer 4 b for an outer ring whichincorporates the tank 9 a therein.

While the description has been given to the example in which theinvention is applied to the spindle, moreover, it is a matter of coursethat the invention can be applied to various apparatuses having arotating shaft other than the spindle and it is apparent that theinvention can also be applied to an apparatus using a rolling bearingother than the angular ball bearing. Furthermore, it is apparent thatthe invention can equally be applied to a rolling bearing using an innerring as a fixed ring in addition to a rolling bearing using an outerring as the fixed ring.

Example 2

FIG. 8A is an axial sectional view showing a rolling bearing deviceaccording to these proposals and FIG. 9 is a sectional view taken alongan X-X line of FIG. 8A. FIG. 10A is a typical sectional view showing anozzle 109 for lubricant supply provided on an oil feeding unit 110which is used in the rolling bearing device according to an example 2 ofthe invention as seen in a radial direction of a bearing and FIG. 10B isa view showing the nozzle 109 seen in a circumferential direction of thebearing.

The rolling bearing device is constituted by an inner ring 101 and anouter ring 102 which serve as raceway members, a plurality of rollingelements (balls 103) disposed in an annular-shaped space S which isformed between opposed surfaces (raceway planes) of these inner andouter rings, and the oil feeding unit 110 for supplying lubricant.

The oil feeding unit 110 includes a pump 105, control means 106 of thepump 105, a tank 107 for storing lubricant and a battery 108, and all ofthem are disposed to be accommodated in the annular-shaped space S ofthe bearing. The control means 106, the tank 107 and the battery 8 takea shape of an almost circular arc as seen in an axial direction, andthese are coupled to the pump 105, thereby constituting anannular-shaped unit member as a whole. The oil feeding unit 110 isattached to a fixed ring side of the opposed surfaces of the bearing (aninner peripheral surface 102 x of the outer ring 102 in this example).

The rolling bearing device according to the example 2 is alsoconstituted by the inner ring 101 and the outer ring 102 which serve asthe raceway members, a plurality of balls 103 disposed in theannular-shaped spaces which is formed between the opposed surfaces ofthe inner and outer rings, and the oil feeding unit 110 for supplyinglubricant.

Moreover, the oil feeding unit 110 includes the pump 105, the controlmeans 106 of the pump 105, the tank 107 for storing lubricant and thebattery 108, and is attached to the fixed ring side of the opposedsurfaces of the bearing (the inner peripheral surface 102 x of the outerring 102), and furthermore, the nozzle 109 having two holes 109 y and109 y for discharging the lubricant to a tip portion 109 x positioned inthe vicinity of rolling elements is provided on an end face at a centralside of the bearing in the pump 105.

The rolling bearing device according to the example 2 features that theholes 109 y and 109 y of the nozzle 109 for discharging the lubricantare formed in the circumferential direction of the bearing,respectively. Moreover, a tip hole 109 z of the nozzle directed in anaxial direction of the bearing is sealed with a resin member 111.

Also in the rolling bearing device having the structure, in the case inwhich the bearing is rotated, an air current is generated in a directionshown in an arrow in the drawing (the circumferential direction of thebearing) in the annular-shaped space S by a rolling motion of the balls103. In the rolling bearing device, however, the holes 109 y and 109 yare provided in the circumferential direction of the bearing which isthe same as the air current so that the air current can pass through aninside of the nozzle 109.

In the rolling bearing device according to the example 2, accordingly, anegative pressure is not generated in the tip portion 109 x of thenozzle so that the lubricant can be prevented from flowing out of thepump 105. Also in the case in which a micropump is employed for the pump105 of the oil feeding unit 110, moreover, it is possible to accuratelycontrol the amount of the lubricant to be supplied into theannular-shaped space S.

Although it is the most desirable that the hole 109 y to be formed onthe nozzle 109 should be provided in the circumferential direction ofthe bearing as shown in FIG. 11A, the direction of the hole of thenozzle in the invention is not particularly restricted thereto. In thecase in which the hole 109 y is formed in a direction other than thecircumferential direction of the bearing as shown in FIG. 11B, moreover,an angle α formed by a centerline A of the hole and a tangential line Lin the circumferential direction of the bearing on a central point O ofthe nozzle is preferably equal to or smaller than 75 degrees and is morepreferably equal to or smaller than 45 degrees. The inventors haveconfirmed, by an experiment, that the negative pressure is reduced moregreatly than in the case in which the hole is formed on the end face ofthe nozzle if the angle α is equal to or smaller than 75 degrees.

In the example 2, a cage 104 for holding the balls 103 at apredetermined interval in the circumferential direction may be providedas shown in FIG. 8B. In this case, a tip portion 109 x of the nozzle 109is disposed to supply the lubricant to the vicinity of the balls 103 orthe cage 104 as shown in FIGS. 10C and 10D.

As shown in FIGS. 8C and 8D, furthermore, the oil feeding unit 110 canalso be disposed on a space 400 corresponding to the fixed ring (theouter ring 102 in these examples). Also in this case, the tip portion109 x of the nozzle 109 is disposed to supply the lubricant to thevicinity of the balls 103 as shown in FIGS. 10A and 10B for FIG. 8C andthe vicinity of the balls 103 or the cage 104 as shown in FIGS. 10C and10D for FIG. 8D in the same manner as FIGS. 8A and 8B.

Further, as shown in FIGS. 8E, 8F and 8G, an intermediate member can bedisposed between the space 400 and a fixed ring (the outer ring 102 inthese examples). The intermediate member functions as a shim. That is,with disposing the intermediate member between the space 400 and thefixed ring, the tip portion of the nozzle for supplying the lubricantcan be adjusted to a position suitable for supplying a small amount oflubricant with respect to the ball 103. Incidentally, the intermediatemember is preferably formed of steel (SPCC, for example), brass(C-2801P, for example) and stainless (SUS304, for example).

FIG. 8E shows an example in which an annular intermediate member 500 isdisposed between the space 400 and the outer ring 402. In this example,the intermediate member has an annular shape. However, the intermediatemember may have C shape to make assembly easy.

FIG. 8F shows an example in which three intermediate members aredisposed between the space 400 and the outer ring 402 at constantintervals on the circumference. Incidentally, although, in FIG. 8F,three intermediate members are disposed, of course, more than threeintermediate members can be disposed. In such a case, the intermediatemembers are preferably disposed at constant intervals on thecircumference.

FIG. 8G shows an example in which three fitting portions (attachingrecesses) 405 are formed on the space 400 and the intermediate members500 are disposed thereto. Incidentally, although the fitting portionsare formed on the space, the attaching recesses may be formed on theouter ring 402.

Of course, the structures of FIGS. 8B and 8G can be suitably combinedwith each other. For example, the feature of the cage of the FIG. 8B canbe combined with the examples of FIGS. 8E and 8G.

Needless to say, with the structures of FIGS. 8B, 8C, 8D, 8E, 8F and 8G,same effects as FIG. 8A can be obtained.

Example 3

Next, an example 3 according to the invention will be described.

FIG. 12A is a typical sectional view showing a nozzle 109 for lubricantsupply provided in an oil feeding unit 110 which is used in a rollingbearing device according to the example 3 of the invention as seen in aradial direction of a bearing, and FIG. 12B is a view showing the nozzle109 seen in a circumferential direction of the bearing.

The example 3 is different from the example 2 in that holes 112 y and112 y are formed in the circumferential direction of the bearing and acylindrical member 112 having a tip hole 112 z sealed with a resinmember 111 is attached to a tip portion 109 x of the nozzle 109. Theseholes 112 y are formed by carrying out a wire cut processing over aperipheral surface of the cylindrical member 112.

By this structure, similarly, a negative pressure is not generated inthe tip portion 109 x of the nozzle and lubricant can be prevented fromflowing out of a pump 105 in the same manner as in the example 2. Alsoin the rolling bearing device according to the example 3, accordingly,the amount of the lubricant to be supplied into an annular-shaped spaceS of the bearing has no waste. Consequently, it is possible to obtain arolling bearing device capable of automatically feeding oil for a longperiod of time.

The number and shape of the holes to be formed in the tip portion of thenozzle and the method of forming them in the invention are notrestricted to these examples but a method of sealing the tip of thenozzle is also optional.

In the example 3, a cage 104 for holding balls 103 at a predeterminedinterval in a circumferential direction may be provided as shown in FIG.8B. In this case, the tip portion 109 x of the nozzle 109 is disposed tosupply the lubricant to the vicinity of the balls 103 or the cage 104 asshown in FIGS. 12C and 12D. Also in the example, as shown in FIGS. 8Cand 8D, the oil feeding unit 110 can also be disposed on a member 400adjacent to a fixed ring (an outer ring 402 in these examples). As shownin FIGS. 8E, 8F and 8G, the intermediate member may be disposed betweenthe space 400 and the fixed ring (the outer ring 402 in these examples)also in this embodiment.

Moreover, the structure of the bearing and that of the oil feeding unitare not restricted to these examples but the invention can be widelyapplied to the rolling bearing device for inserting a lubricant feedingnozzle to the vicinity of rolling elements or the cage and supplying thelubricant by means of a pump.

Example 4

FIG. 13A is a typical sectional view showing a nozzle 109 for lubricantsupply provided in an oil feeding unit 110 used in a rolling bearingdevice according to an example 4 of the invention as seen in a radialdirection of a bearing, and FIG. 13B is a view showing the nozzle 9 seenin a circumferential direction of the bearing. Since a whole structureof the rolling bearing device is the same as that in the example 2 shownin FIGS. 8A and 9, detailed description thereof will be omitted.

A rolling bearing device according to the example is also constituted byan inner ring 101 and an outer ring 102 which serve as raceway members,a plurality of balls 103 disposed in an annular-shaped space S which isformed between opposed surfaces of these inner and outer rings, and theoil feeding unit 110 for supplying lubricant.

Moreover, the oil feeding unit 110 includes a pump 105, control means106 of the pump 105, a tank 107 for storing lubricant and a battery 108and is attached to a fixed ring side of the opposed surfaces of thebearing (an inner peripheral surface 102 x of the outer ring 102), andfurthermore, the nozzle 109 having a hole 9 y for discharging thelubricant to a tip portion 109 x positioned in the vicinity of rollingelements is provided on an end face at a central side of the bearing inthe pump 105.

The rolling bearing device according to the example features that an endface of the tip portion 109 x of the nozzle is formed in a slant faceopened toward an upstream side of an air current generated in theannular-shaped space S by a relative rotation of the inner and outerrings.

Also in the rolling bearing device having the structure, in the case inwhich the bearing is rotated, an air current is generated in a directionshown in an arrow in the drawing (the circumferential direction of thebearing) in the annular-shaped space S by a rolling motion of the balls103. In the rolling bearing device, however, the tip of the nozzle 109is formed in the slant face opposed to the upstream side of the aircurrent. Therefore, the air current hits on an inner peripheral surface109 z of the nozzle 109 so that the lubricant is pressed into a tube ofthe nozzle 109 by a wind pressure which is generated.

In the rolling bearing device according to the example, accordingly, anegative pressure is not generated in the tip portion 109 x of thenozzle so that the lubricant can be prevented from flowing out of thepump 105. Also in the case in which a micropump is employed for the pump105 of the oil feeding unit 110, moreover, it is possible to accuratelycontrol the amount of the lubricant to be supplied into theannular-shaped space S.

It is desirable that the slant face (open surface) should be formed onthe tip of the nozzle 109 in such a manner that an angle α formed by acentral axis of the nozzle 109 is 10 to 80 degrees. Depending onconditions such as a rotating speed, the inventors have confirmed, by anexperiment, that the negative pressure generated in the nozzle tube isalmost zero when the angle α is 60 degrees.

In the example 4, a cage 104 for holding the balls 103 at apredetermined interval in the circumferential direction may be providedas shown in FIG. 8B. In this case, the tip portion 109 x of the nozzle109 is disposed to supply the lubricant to the vicinity of the balls 103or the cage 104 as shown in FIGS. 13C and 13D. Also in the example, asshown in FIGS. 8C and 8D, the oil feeding unit 110 can also be disposedon a member 400 adjacent to a fixed ring (an outer ring 402 in theseexamples). As shown in FIGS. 8E, 8F and 8G, the intermediate member maybe disposed between the space 400 and the fixed ring (the outer ring 402in these examples) also in this embodiment.

Example 5

Next, an example 5 according to the invention will be described.

FIG. 14A is a typical sectional view showing a nozzle 109 for lubricantsupply provided in an oil feeding unit 110 which is used in a rollingbearing device according to the example 5 of the invention as seen in aradial direction of a bearing, and FIG. 14B is a view showing the nozzle109 seen in a circumferential direction of the bearing.

The example 5 is different from the example 4 in that a member 113(which will be hereinafter referred to as a “baffle member”) for leadingan air current generated in an annular-shaped space S by a relativerotation of inner and outer rings toward a hole 109 y of the nozzle 109is provided on a tip portion 109 x of the nozzle 109.

The baffle member 113 takes a cylindrical shape in which an insidediameter is almost equal to an outside diameter of the nozzle 109 and anopening on an end is cut obliquely so that an open surface having a hole113 y is formed. Moreover, the baffle member 113 is fixed to the tipportion 109 x of the nozzle with an adhesive, for example, with the opensurface (slant face) being directed toward an upstream side of the aircurrent generated by the relative rotation of the bearing.

By the structure, similarly, the air current generated by the rotationof the bearing hits on an inner peripheral surface 113 z of the bafflemember 113 so that lubricant is pressed into the tube of the nozzle 109by a wind pressure thereof in the same manner as in the example 4. Inthe rolling bearing device according to the example, accordingly, anegative pressure is not generated in the tip portion 109 x of thenozzle but the lubricant can be prevented from flowing out of a pump105.

In the example 5, a cage 104 for holding balls 103 at a predeterminedinterval in the circumferential direction may be provided as shown inFIG. 8B. In this case, the tip portion 109 x of the nozzle 109 isdisposed to supply the lubricant to the vicinity of the balls 103 or thecage 104 as shown in FIGS. 14C and 14D. Also in the example, as shown inFIGS. 8C and 8D, the oil feeding unit 110 can also be disposed on amember 400 adjacent to a fixed ring (an outer ring 402 in theseexamples). As shown in FIGS. 8E, 8F and 8G, the intermediate member maybe disposed between the space 400 and the fixed ring (the outer ring 402in these examples) also in this embodiment.

Example 6

In the invention, the shape of the baffle member provided on the tipportion 109 x of the nozzle 109 is not restricted to the example.Moreover, the opening does not need to be the slant face but a bafflemember 114 taking a shape according to an example 6 shown in FIG. 15 maybe provided, for example. The baffle member 114 takes a cylindricalshape in which an inner diameter is almost equal to the outside diameterof the nozzle 109 and an opening on one end is cut rectangularly so thatan open face having a hole 114 y is formed. Furthermore, the bafflemember 114 is fixed to the tip portion 109 x of the nozzle with anadhesive, for example, with the open surface directed toward an upstreamside of an air current generated by the relative rotation of thebearing. By the baffle member 114, similarly, the air current hits on aninner peripheral surface 114 z which is exposed so that the sameadvantages as those in the example 5 can be produced.

In the example 6, a cage 104 for holding balls 103 at a predeterminedinterval in the circumferential direction may be provided as shown inFIG. 8B. In this case, the tip portion 109 x of the nozzle 109 isdisposed to supply the lubricant to the vicinity of the balls 103 or thecage 104 as shown in FIGS. 15C and 15D. Also in the example, as shown inFIGS. 8C and 8D, an oil feeding unit 110 can also be disposed on amember 400 adjacent to a fixed ring (an outer ring 402 in theseexamples). As shown in FIGS. 8E, 8F and 8G, the intermediate member maybe disposed between the space 400 and the fixed ring (the outer ring 402in these examples) also in this embodiment.

Example 7

FIG. 16A is a typical sectional view showing a nozzle for lubricantsupply provided in an oil feeding unit 10 used in a rolling bearingdevice according to an example 7 of the invention as seen in a radialdirection of a bearing, and FIG. 16B is a view showing the nozzle seenin a circumferential direction of the bearing. Since a whole structureof the rolling bearing device is the same as that in the example 2 shownin FIGS. 8 and 9, detailed description thereof will be omitted.

A rolling bearing device according to the example is also constituted byan inner ring 1 and an outer ring 2 which serve as raceway members, aplurality of balls 103 disposed in an annular-shaped space S which isformed between opposed surfaces of these inner and outer rings, a cage 4for holding these balls 103 at a predetermined interval in acircumferential direction, and an oil feeding unit 110 for supplyinglubricant.

Moreover, the oil feeding unit 110 includes a pump 105, control means106 of the pump 105, a tank 107 for storing lubricant and a battery 108and is attached to a fixed ring side of the opposed surfaces of thebearing (an inner peripheral surface 2 x of the outer ring 2), andfurthermore, a nozzle 211 provided with a hole 211 c for discharginglubricant in a tip portion 211 a is disposed on an end face at a centralside of the bearing of the pump 105.

The rolling bearing device according to the example features that alarge diameter portion 211 d having a larger diameter than diameters ofthe other portions is formed in the tip portion 211 a of the nozzle 211for supplying lubricant O.

Also in the rolling bearing device having the structure, in the case inwhich the bearing is rotated, an air current is generated in a direction(a circumferential direction of the bearing) shown in an arrow in thedrawing in the annular-shaped space S by a rolling motion of the balls103. In the rolling bearing device, however, the large diameter portion211 d to be lubricant holding portion is formed on the tip of the nozzle211. Therefore, the lubricant O which is discharged is not moved in adirection of a base portion 211 b of the nozzle but is collected as oildrops vertically and downward from the large diameter portion 211 d.

In the rolling bearing device according to the example, accordingly, thedischarged lubricant O can be stably dropped into the vicinity of theballs 103 or the vicinity of the cage 4 at the highest efficiency.Moreover, the lubricant to be supplied has no waste so that it ispossible to maintain an excellent bearing lubrication with a smallamount of the lubricant.

The lubricant holding portion (the large diameter portion 211 d)provided on the tip of the nozzle 211 does not need to be formeduniformly in the circumferential direction of the nozzle 211 but maytake any shape swollen (protruded) at least vertically and downward inthe bearing.

In the example 7, a cage 104 for holding the balls 103 at apredetermined interval in the circumferential direction may be providedas shown in FIG. 8B. In this case, a tip portion 109 x of a nozzle 109is disposed to supply the lubricant to the vicinity of the balls 103 orthe cage 104 as shown in FIGS. 16C and 16D. Also in the example, asshown in FIGS. 8C and 8D, the oil feeding unit 110 can also be disposedon a member 400 adjacent to a fixed ring (an outer ring 402 in theseexamples). As shown in FIGS. 8E, 8F and 8G, the intermediate member maybe disposed between the space 400 and the fixed ring (the outer ring 402in these examples) also in this embodiment.

Examples 8 and 9

Next, examples 8 and 9 according to the invention will be described.

FIGS. 17A and 18A are typical sectional views showing a nozzle forlubricant supply provided in an oil feeding unit 10 used in a rollingbearing device according to examples 8 and 9 of the invention as seen ina radial direction of a bearing, and FIGS. 17B and 18B are views showingthe nozzle seen in a circumferential direction of the bearing.

The example 8 is different from the example 7 in that a lubricantholding portion for collecting the discharged lubricant as an oil dropis formed by setting an opening diameter of a hole 12 c on a tip of thenozzle to be larger than a diameter of an inner peripheral surface 12 yin the other portions.

In the example 9, moreover, the lubricant holding portion is formed bymeans of an annular-shaped member 213 fitted on a nozzle tip portion 109x. The annular-shaped member 213 is fixed to an outer peripheral surface109 a of a nozzle 109 with an adhesive, for example.

By these structures, similarly, the lubricant discharged from a pump 105is collected as an oil drop vertically and downward from the lubricantholding portion (the nozzle tip portion 109 x or the annular-shapedmember 213) and is not moved in a direction of a base portion of thenozzle. Accordingly, the rolling bearing devices according to theseexamples can also stably drop the discharged lubricant into the vicinityof balls 103. Moreover, the lubricant to be supplied has no waste and anexcellent bearing lubrication can also be maintained with a small amountof the lubricant.

In the examples 8 and 9, a cage 104 for holding the balls 103 at apredetermined interval in the circumferential direction may be providedas shown in FIG. 8B. In this case, the tip portion 109 x of the nozzle109 is disposed to supply the lubricant to the vicinity of the balls 103or the cage 104 as shown in FIGS. 17C, 17D, 18C and 18D. Also in theseexamples, as shown in FIGS. 8C and 8D, an oil feeding unit 110 can alsobe disposed on a member 400 adjacent to a fixed ring (an outer ring 402in these examples). As shown in FIGS. 8E, 8F and 8G, the intermediatemember may be disposed between the space 400 and the fixed ring (theouter ring 402 in these examples) also in this embodiment.

Also in these examples, the lubricant holding portion provided on thetip of the nozzle does not need to be formed uniformly in thecircumferential direction of the nozzle but preferably takes any shapeprotruded at least vertically and downward in the bearing. For instance,an opening shape of a tip portion 109 z according to the example 8 mayinclude a shape of a petal and a shape of a star in the circumferentialdirection of the nozzle in addition to a shape of a trumpet which isillustrated.

Moreover, the structure of the bearing and that of the oil feeding unitare not restricted to those of the examples 2 to 9 but the invention canbe widely applied to a rolling bearing device for inserting thelubricant feeding nozzle to the vicinity of the rolling elements or thecage and supplying lubricant by means of a pump.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an axial sectional view showing a structure of a spindleaccording to an example 1 of the invention.

FIG. 2 is an enlarged view showing a main part in FIG. 1.

FIG. 3 is a front view showing a spacer 4 for an outer ring according tothe example 1 of the invention as seen in a direction shown in an arrowA of FIG. 2.

FIG. 4 is a view showing a whole structure of an oil feeding unit usedin the example 1 according to the invention, including a typical viewillustrating a mechanical structure and a block diagram illustrating anelectrical structure together.

FIG. 5 is an axial sectional view showing a main part according to avariant of the first example in accordance with the invention.

FIG. 6 is an axial sectional view showing a main part according toanother variant of the first example in accordance with the invention.

FIG. 7 is an axial sectional view showing a structure of a main partaccording to a further variant of the first example in accordance withthe invention.

FIG. 8A is a sectional view in an axial direction, illustrating anexample of a structure of a rolling bearing device comprising an oilfeeding unit.

FIG. 8B is a sectional view in an axial direction, illustrating avariant of the rolling bearing device comprising the oil feeding unit.

FIG. 8C is a sectional view in an axial direction, illustrating avariant of the rolling bearing device comprising the oil feeding unit.

FIG. 8D is a sectional view in an axial direction, illustrating avariant of the rolling bearing device comprising the oil feeding unit.

FIG. 8E is a sectional view in an axial direction, illustrating avariant of the rolling bearing device comprising the oil feeding unit.

FIG. 8F is a sectional view in an axial direction, illustrating avariant of the rolling bearing device comprising the oil feeding unit.

FIG. 8G is a sectional view in an axial direction, illustrating avariant of the rolling bearing device comprising the oil feeding unit.

FIG. 9 is a sectional view taken along an X-X line in FIG. 8.

FIG. 10A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to anexample 2 of the invention as seen in a radial direction of a bearing.

FIG. 10B is a view showing the nozzle in FIG. 10A as seen in acircumferential direction of the bearing.

FIG. 10C is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to a variantof the example 2 in accordance with the invention as seen in the radialdirection of the bearing.

FIG. 10D is a view showing the nozzle in FIG. 10C as seen in thecircumferential direction of the bearing.

FIG. 11A is a view showing a nozzle for lubricant supply according to anembodiment of the invention as seen in an axial direction of a bearing.

FIG. 11B is a view for explaining a direction of a hole formed on thenozzle in FIG. 11A.

FIG. 12A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to anexample 3 of the invention as seen in a radial direction of the bearing.

FIG. 12B is a view showing the nozzle in FIG. 12A as seen in acircumferential direction of the bearing.

FIG. 12C is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to a variantof the example 3 in accordance with the invention as seen in the radialdirection of the bearing.

FIG. 12D is a view showing the nozzle in FIG. 12C as seen in thecircumferential direction of the bearing.

FIG. 13A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to anexample 4 of the invention as seen in the radial direction of thebearing.

FIG. 13B is a view showing the nozzle in FIG. 13A as seen in thecircumferential direction of the bearing.

FIG. 13C is a view showing a nozzle for lubricant supply provided in theoil feeding unit used in the rolling bearing device according to avariant of the example 4 in accordance with the invention as seen in theradial direction of the bearing.

FIG. 13D is a view showing the nozzle in FIG. 13C as seen in thecircumferential direction of the bearing.

FIG. 14A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in the rolling bearing device according to anexample 5 of the invention as seen in the radial direction of thebearing.

FIG. 14B is a view showing the nozzle in FIG. 14A as seen in thecircumferential direction of the bearing.

FIG. 14C is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to a variantof the example 5 in accordance with the invention as seen in the radialdirection of the bearing.

FIG. 14D is a view showing the nozzle in FIG. 14C as seen in thecircumferential direction of the bearing.

FIG. 15A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to anexample 6 of the invention as seen in the radial direction of thebearing.

FIG. 15B is a view showing the nozzle in FIG. 15A as seen in thecircumferential direction of the bearing.

FIG. 15C is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to a variantof the example 6 in accordance with the invention as seen in the radialdirection of the bearing.

FIG. 15D is a view showing the nozzle in FIG. 15C as seen in thecircumferential direction of the bearing.

FIG. 16A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to anexample 7 of the invention as seen in the radial direction of thebearing.

FIG. 16B is a view showing the nozzle in FIG. 16A as seen in thecircumferential direction of the bearing.

FIG. 16C is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to a variantof the example 7 in accordance with the invention as seen in the radialdirection of the bearing.

FIG. 16D is a view showing the nozzle in FIG. 16C as seen in thecircumferential direction of the bearing.

FIG. 17A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to anexample 8 of the invention as seen in the radial direction of thebearing.

FIG. 17B is a view showing the nozzle in FIG. 17A as seen in thecircumferential direction of the bearing.

FIG. 17C is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to a variantof the example 8 in accordance with the invention as seen in the radialdirection of the bearing.

FIG. 17D is a view showing the nozzle in FIG. 10C as seen in thecircumferential direction of the bearing.

FIG. 18A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to anexample 9 of the invention as seen in the radial direction of thebearing.

FIG. 18B is a view showing the nozzle in FIG. 18A as seen in thecircumferential direction of the bearing.

FIG. 18C is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a rolling bearing device according to a variantof the example 9 in accordance with the invention as seen in the radialdirection of the bearing.

FIG. 18D is a view showing the nozzle in FIG. 18C as seen in thecircumferential direction of the bearing.

FIG. 19 is a view including a sectional view illustrating an example ofa structure of a conventional spindle using an oil air lubricatingmethod and a block diagram illustrating an example of a structure of anexternal device for lubrication together.

FIG. 20 is an axial sectional view showing an example of a structure ofa conventional rolling bearing device incorporating an oil feeding unitfor lubrication in a rolling bearing.

FIG. 21A is a view showing a nozzle for lubricant supply provided in anoil feeding unit used in a conventional rolling bearing device as seenin a radial direction of a bearing.

FIG. 21B is a view showing the nozzle in FIG. 21A as seen in acircumferential direction of the bearing.

FIG. 22 is a view for explaining problems of the nozzle for lubricantsupply provided in the oil feeding unit used in the conventional rollingbearing device.

The invention claimed is:
 1. A rolling bearing device comprising: a pairof raceway members which are disposed concentrically and define anannular-shaped space radially and axially therebetween; rolling elementsdisposed in the annular-shaped space; and a pump including a pipe-shapednozzle, the pump being disposed in the annular-shaped space or adjacentthereof, wherein a tip portion of the nozzle is disposed in theannular-shaped space so as to supply lubricant to a vicinity of therolling elements, wherein the nozzle is provided with a hole fordischarging lubricating oil such that an opening of the hole faces insubstantially a circumferential direction of the annular-shaped space,wherein the opening of the hole is disposed on a circumferential surfaceof the nozzle at a position spaced from a tip end of the nozzle, whereinthe tip end of the nozzle, which is directed in an axial direction ofthe raceway member, is closed, and wherein a tip hole in the tip end ofthe nozzle, which is directed in the axial direction of the racewaymember, is closed with a sealing member.
 2. The rolling bearing deviceaccording to claim 1, further comprising a cage for holding the rollingelements in the annular-shaped space at predetermined intervals, the tipportion of the nozzle being disposed in the annular-shaped space so asto supply the lubricant to the vicinity of the rolling elements or thecage.
 3. The rolling bearing device according to claim 2, wherein thehole axially overlaps the cage.
 4. The rolling bearing device accordingto claim 1, wherein the hole of the nozzle is formed in a positioncorresponding to a circumferential direction of the bearing on aperipheral surface of the nozzle.
 5. The rolling bearing deviceaccording to claim 1, wherein the hole is formed such that a portion ofthe nozzle is disposed between the hole and an axially distal end of thenozzle.
 6. The rolling bearing device according to claim 1, wherein thehole is formed in a position such that a portion of the nozzle separatesthe hole, in an axial direction of the nozzle, from a distal end of thenozzle which is opposite the pump.
 7. The rolling bearing deviceaccording to claim 1, wherein the hole comprises a plurality of holes.8. The rolling bearing device according to claim 1, wherein the holecomprises a plurality of holes, and wherein the plurality of holes opento face in opposite directions.
 9. The rolling bearing device accordingto claim 1, wherein the hole faces a direction perpendicular to adirection an axially distal end face of the nozzle faces.
 10. Therolling bearing device according to claim 1, wherein the tip portion ofthe nozzle faces in the axial direction.
 11. The rolling bearing deviceaccording to claim 1, wherein the tip portion of the nozzle axiallyoverlaps the rolling elements.
 12. The rolling bearing device accordingto claim 1, wherein a distal end face of a distal end of the nozzlefaces in the axial direction.
 13. The rolling bearing device accordingto claim 1, wherein the nozzle extends in an axial direction from aportion of the nozzle connected to the pump to a distal end of thenozzle.
 14. The rolling bearing device according to claim 1, wherein thehole is configured so as to reduce a negative pressure in the nozzlecaused by a wind pressure generated by a rolling motion of the rollingelements.
 15. The rolling bearing device according to claim 1, whereinthe sealing member comprises a resin member.
 16. The rolling bearingdevice according to claim 1, wherein an end of the nozzle opposite thepump is sealed with the sealing member disposed in the end of the nozzlesuch that the hole is disposed between a side of the sealing memberclosest to the pump and the pump.
 17. A rolling bearing devicecomprising: a pair of raceway members which are disposed concentricallyand define an annular-shaped space radially and axially therebetween;rolling elements disposed in the annular-shaped space; and a pumpincluding a pipe-shaped nozzle, the pump being disposed in theannular-shaped space or adjacent thereof, wherein a tip portion of thenozzle is disposed in the annular-shaped space so as to supply lubricantto a vicinity of the rolling elements, wherein the nozzle is providedwith a hole for discharging lubricating oil such that an opening of thehole faces in substantially a circumferential direction of theannular-shaped space, and wherein an end of the nozzle opposite the pumpis sealed with a resin member such that the hole is disposed between aside of the resin member closest to the pump and the pump.
 18. A rollingbearing device comprising: a pair of raceway members which are disposedconcentrically and define an annular-shaped space radially and axiallytherebetween; rolling elements disposed in the annular-shaped space; anda pump including a pipe-shaped nozzle, the pump being disposed in theannular-shaped space or adjacent thereof, wherein a tip portion of thenozzle is disposed in the annular-shaped space so as to supply lubricantto a vicinity of the rolling elements, wherein the nozzle is providedwith a hole for discharging lubricating oil such that an opening of thehole faces in a direction excluding an axial direction and a radialdirection of the rolling bearing device, and wherein an end of thenozzle opposite the pump is sealed with a resin member such that thehole is disposed between a side of the resin member closest to the pumpand the pump.
 19. The rolling bearing device according to claim 18,wherein an angle formed by a centerline of the hole and a tangentialline in the circumferential direction on a central point of the nozzleis equal to or less than 75 degrees.
 20. The rolling bearing deviceaccording to claim 18, wherein an angle formed by a centerline of thehole and a tangential line in the circumferential direction on a centralpoint of the nozzle is equal to or less than 45 degrees.